On Tue, 9 Jan 2024 at 12:44, Jonathan Wakely <jwak...@redhat.com> wrote: > > I was talking to Matthias Klose about enabling libstdc++_libbacktrace.a > for Ubuntu's gcc package and I realised that it would be preferable if > the gcc-13 branch had those libbacktrace symbols in libstdc++exp.a. I > already did that for trunk with r14-3812-gb96b554592c5cb and trunk no > longer installs libstdc++_libbacktrace.a at all. > > Removing libstdc++_libbacktrace.a for GCC 13.3 would be inappropriate > for a stable release branch, so this partial backport duplicates the > libstdc++_libbacktrace.a symbols in libstdc++exp.a but still installs > libstdc++_libbacktrace.a as well. This gives users a smoother > transition from GCC 13 to GCC 14. They can continue using > -lstdc++_libbacktrace with GCC 13, or they can switch to > -lstdc++exp now and be ready for GCC 14.
This didn't actually work though, see https://gcc.gnu.org/pipermail/gcc-patches/2024-February/644822.html for the explanation and fix, which I'll backport to gcc-13. > > Any objections? > > Tested x86_64-linux. > > If I push this I'll also add a 13.3 section to the bottom of > https://gcc.gnu.org/gcc-13/changes.html#13.2 documenting it. > > -- >8 -- > > This consolidates the three static archives for extensions into one, so > that -lstdc++exp can be used to provide the definitions of all unstable > library features. > > For this gcc-13 backport libstdc++_libbacktrace.a is still installed, > but its contents are duplicated in libstdc++exp.a. This means that users > can start using -lstdc++exp with GCC 13.3 if they want, but existing > Makefiles can continue to use -lstdc++_libbacktrace for any GCC 13.x > release. > > The libstdc++fs.a archive is still installed, but its contents are > duplicated in libstdc++exp.a now. This means -lstdc++exp can be used > instead of -lstdc++fs. For targets using the GNU linker we should > consider replacing libstdc++fs.a with a linker script that does > INPUT(libstdc++exp.a). > > The tests for <experimental/filesystem> could be changed to use > -lstdc++exp instead of -lstdc++fs, which would allow removing > src/filesystem/.libs from the LDFLAGS in scripts/testsuite_flags.in, > but that can be done at a later date. > > libstdc++-v3/ChangeLog: > > * doc/html/manual/*: Regenerate. > * doc/xml/manual/using.xml: Update documentation on linking. > * scripts/testsuite_flags.in: Adjust LDFLAGS to find > libstdc++exp instead of libstdc++_libbacktrace. > * src/c++20/Makefile.am: Fix comment. > * src/c++20/Makefile.in: Regenerate. > * src/experimental/Makefile.am: Use LIBADD to include other > libraries. > * src/experimental/Makefile.in: Regenerate. > * testsuite/19_diagnostics/stacktrace/current.cc: Adjust > dg-options to use -lstdc++exp. > * testsuite/19_diagnostics/stacktrace/entry.cc: Likewise. > * testsuite/19_diagnostics/stacktrace/stacktrace.cc: Likewise. > * testsuite/23_containers/vector/debug/assign4_backtrace_neg.cc: > Likewise. > > (cherry picked from commit b96b554592c5cbb6a2c1797ffcb5706fd295f4fd) > --- > libstdc++-v3/doc/html/manual/using.html | 26 +++++++------ > .../html/manual/using_dynamic_or_shared.html | 4 ++ > libstdc++-v3/doc/xml/manual/using.xml | 37 ++++++++++--------- > libstdc++-v3/scripts/testsuite_flags.in | 8 ++-- > libstdc++-v3/src/c++20/Makefile.am | 2 +- > libstdc++-v3/src/c++20/Makefile.in | 2 +- > libstdc++-v3/src/experimental/Makefile.am | 18 +++++++++ > libstdc++-v3/src/experimental/Makefile.in | 13 ++++++- > .../19_diagnostics/stacktrace/current.cc | 2 +- > .../19_diagnostics/stacktrace/entry.cc | 2 +- > .../19_diagnostics/stacktrace/stacktrace.cc | 2 +- > .../vector/debug/assign4_backtrace_neg.cc | 2 +- > 12 files changed, 77 insertions(+), 41 deletions(-) > > diff --git a/libstdc++-v3/doc/xml/manual/using.xml > b/libstdc++-v3/doc/xml/manual/using.xml > index 3a507fc1671..7276cad0feb 100644 > --- a/libstdc++-v3/doc/xml/manual/using.xml > +++ b/libstdc++-v3/doc/xml/manual/using.xml > @@ -100,30 +100,27 @@ > </entry> > </row> > > - <row> > - <entry><literal>-lstdc++fs</literal></entry> > - <entry>Linking to <filename class="libraryfile">libstdc++fs</filename> > - is required for use of the Filesystem library extensions in > - <filename > class="headerfile"><experimental/filesystem></filename>. > - </entry> > - </row> > - > <row> > <entry><literal>-lstdc++exp</literal></entry> > - <entry>Linking to <filename class="libraryfile">libstdc++exp</filename> > - is required for use of the C++ Contracts extensions enabled by > - <literal>-fcontracts</literal>. > + <entry>Linking to <filename > class="libraryfile">libstdc++exp.a</filename> > + is required for use of experimental C++ library features. > + This currently provides support for the C++23 types defined in the > + <filename class="headerfile"><stacktrace></filename> header, > + the Filesystem library extensions defined in the > + <filename > class="headerfile"><experimental/filesystem></filename> > + header, > + and the Contracts extensions enabled by > <literal>-fcontracts</literal>. > </entry> > </row> > > <row> > - <entry><literal>-lstdc++_libbacktrace</literal></entry> > - <entry>Until C++23 support is non-experimental, linking to > - <filename class="libraryfile">libstdc++_libbacktrace.a</filename> > - is required for use of the C++23 type > - <classname>std::stacktrace</classname> > - and related types in > - <filename class="headerfile"><stacktrace></filename>. > + <entry><literal>-lstdc++fs</literal></entry> > + <entry>Linking to <filename > class="libraryfile">libstdc++fs.a</filename> > + is another way to use the Filesystem library extensions defined in > the > + <filename > class="headerfile"><experimental/filesystem></filename> > + header. > + The <filename class="libraryfile">libstdc++exp.a</filename> library > + also provides all the symbols contained in this library. > </entry> > </row> > > @@ -1710,6 +1707,10 @@ A quick read of the relevant part of the GCC > and link with <option>-lstdc++fs</option>. The library implementation > is incomplete on non-POSIX platforms, specifically Windows is only > partially supported. > + Since GCC 14, <filename class="libraryfile">libstdc++exp.a</filename> > + also contains the definitions for this library, > + so <option>-lstdc++exp</option> can be used instead of > + <option>-lstdc++fs</option>. > </para> > > <para> > diff --git a/libstdc++-v3/scripts/testsuite_flags.in > b/libstdc++-v3/scripts/testsuite_flags.in > index 18748f0f9ce..8bf4918287a 100755 > --- a/libstdc++-v3/scripts/testsuite_flags.in > +++ b/libstdc++-v3/scripts/testsuite_flags.in > @@ -78,14 +78,14 @@ case ${query} in > ;; > --cxxldflags) > FS_LDFLAGS= > - BT_LDFLAGS= > + EXP_LDFLAGS= > if [ -d ${BUILD_DIR}/src/filesystem/.libs ]; then > FS_LDFLAGS=-L${BUILD_DIR}/src/filesystem/.libs > fi > - if [ -d ${BUILD_DIR}/src/libbacktrace/.libs ]; then > - BT_LDFLAGS=-L${BUILD_DIR}/src/libbacktrace/.libs > + if [ -d ${BUILD_DIR}/src/experimental/.libs ]; then > + EXP_LDFLAGS=-L${BUILD_DIR}/src/experimental/.libs > fi > - SECTIONLDFLAGS="@SECTION_LDFLAGS@ @LIBICONV@ $FS_LDFLAGS $BT_LDFLAGS" > + SECTIONLDFLAGS="@SECTION_LDFLAGS@ @LIBICONV@ $FS_LDFLAGS $EXP_LDFLAGS" > echo ${SECTIONLDFLAGS} > ;; > *) > diff --git a/libstdc++-v3/src/c++20/Makefile.am > b/libstdc++-v3/src/c++20/Makefile.am > index 0bc8a7b832a..e947855e6ae 100644 > --- a/libstdc++-v3/src/c++20/Makefile.am > +++ b/libstdc++-v3/src/c++20/Makefile.am > @@ -22,7 +22,7 @@ > > include $(top_srcdir)/fragment.am > > -# Convenience library for C++17 runtime. > +# Convenience library for C++20 runtime. > noinst_LTLIBRARIES = libc++20convenience.la > > headers = > diff --git a/libstdc++-v3/src/experimental/Makefile.am > b/libstdc++-v3/src/experimental/Makefile.am > index 3b962e7d804..1c7cea7e846 100644 > --- a/libstdc++-v3/src/experimental/Makefile.am > +++ b/libstdc++-v3/src/experimental/Makefile.am > @@ -24,6 +24,18 @@ include $(top_srcdir)/fragment.am > > toolexeclib_LTLIBRARIES = libstdc++exp.la > > +if ENABLE_FILESYSTEM_TS > +filesystem_lib = $(top_builddir)/src/filesystem/libstdc++fs.la > +else > +filesystem_lib = > +endif > + > +if ENABLE_BACKTRACE > +backtrace_lib = $(top_builddir)/src/libbacktrace/libstdc++_libbacktrace.la > +else > +backtrace_lib = > +endif > + > headers = > > sources = \ > @@ -33,6 +45,12 @@ sources = \ > > libstdc__exp_la_SOURCES = $(sources) > > +libstdc__exp_la_LIBADD = \ > + $(filesystem_lib) $(backtrace_lib) > + > +libstdc__exp_la_DEPENDENCIES = \ > + $(filesystem_lib) $(backtrace_lib) > + > # AM_CXXFLAGS needs to be in each subdirectory so that it can be > # modified in a per-library or per-sub-library way. Need to manually > # set this option because CONFIG_CXXFLAGS has to be after > diff --git a/libstdc++-v3/testsuite/19_diagnostics/stacktrace/current.cc > b/libstdc++-v3/testsuite/19_diagnostics/stacktrace/current.cc > index 184e23b460e..f6c860fc7a4 100644 > --- a/libstdc++-v3/testsuite/19_diagnostics/stacktrace/current.cc > +++ b/libstdc++-v3/testsuite/19_diagnostics/stacktrace/current.cc > @@ -1,4 +1,4 @@ > -// { dg-options "-std=gnu++23 -lstdc++_libbacktrace" } > +// { dg-options "-std=gnu++23 -lstdc++exp" } > // { dg-do run { target c++23 } } > // { dg-require-effective-target stacktrace } > > diff --git a/libstdc++-v3/testsuite/19_diagnostics/stacktrace/entry.cc > b/libstdc++-v3/testsuite/19_diagnostics/stacktrace/entry.cc > index a222c425b20..f0406953d03 100644 > --- a/libstdc++-v3/testsuite/19_diagnostics/stacktrace/entry.cc > +++ b/libstdc++-v3/testsuite/19_diagnostics/stacktrace/entry.cc > @@ -1,4 +1,4 @@ > -// { dg-options "-std=gnu++23 -lstdc++_libbacktrace" } > +// { dg-options "-std=gnu++23 -lstdc++exp" } > // { dg-do run { target c++23 } } > // { dg-require-effective-target stacktrace } > > diff --git a/libstdc++-v3/testsuite/19_diagnostics/stacktrace/stacktrace.cc > b/libstdc++-v3/testsuite/19_diagnostics/stacktrace/stacktrace.cc > index 8dfdf4739be..0a358b7b8ff 100644 > --- a/libstdc++-v3/testsuite/19_diagnostics/stacktrace/stacktrace.cc > +++ b/libstdc++-v3/testsuite/19_diagnostics/stacktrace/stacktrace.cc > @@ -1,4 +1,4 @@ > -// { dg-options "-std=gnu++23 -lstdc++_libbacktrace" } > +// { dg-options "-std=gnu++23 -lstdc++exp" } > // { dg-do run { target c++23 } } > // { dg-require-effective-target stacktrace } > > diff --git > a/libstdc++-v3/testsuite/23_containers/vector/debug/assign4_backtrace_neg.cc > b/libstdc++-v3/testsuite/23_containers/vector/debug/assign4_backtrace_neg.cc > index 520788d5cb7..43a82fb1201 100644 > --- > a/libstdc++-v3/testsuite/23_containers/vector/debug/assign4_backtrace_neg.cc > +++ > b/libstdc++-v3/testsuite/23_containers/vector/debug/assign4_backtrace_neg.cc > @@ -1,5 +1,5 @@ > // { dg-do run { xfail *-*-* } } > -// { dg-options "-D_GLIBCXX_DEBUG_BACKTRACE -lstdc++_libbacktrace" } > +// { dg-options "-D_GLIBCXX_DEBUG_BACKTRACE -lstdc++exp" } > // { dg-require-effective-target stacktrace } > > #include <debug/vector> > -- > 2.43.0 >
